math help

What is 20/17 + 4/5?

What is 20/17 + 4/5?

Here's how we add

20
17
+
4
5

Step 1

Of course, you can't add two fractions if the denominators (bottom numbers) don't match. To get a common denominator, multiply the denominators together. Then we fix the numerators by multiplying each one by their other term's denominator.

Now you multiply 20 by 5, and get 100, then we multiply 17 by 5 and get 85.

20/17 times 5

Do the same for the second term. We multiply 4 by 17, and get 68, then multiply 17 by 5 and get 85.

4/5 times 17

The problem now has new fractions to add:

100
85
+
68
85

Step 2

Since our denominators match, we can add the numerators.

100 + 68 = 168

The sum we get is

168
85

Step 3

The last step is to reduce the fraction if we can.

To find out, we try dividing it by 2...

Nope. Try the next prime number, 3...

Nope. Try the next prime number, 5...

Nope. Try the next prime number, 7...

Nope. Try the next prime number, 11...

Nope. Try the next prime number, 13...

Nope. Try the next prime number, 17...

Nope. Try the next prime number, 19...

Nope. Try the next prime number, 23...

Nope. Try the next prime number, 29...

Nope. Try the next prime number, 31...

Nope. Try the next prime number, 37...

Nope. Try the next prime number, 41...

Nope. Try the next prime number, 43...

Nope. Try the next prime number, 47...

Nope. Try the next prime number, 53...

Nope. Try the next prime number, 59...

Nope. Try the next prime number, 61...

Nope. Try the next prime number, 67...

Nope. Try the next prime number, 71...

Nope. Try the next prime number, 73...

Nope. Try the next prime number, 79...

Nope. Try the next prime number, 83...

Nope. Try the next prime number, 89...

No good. 89 is larger than 85. So we're done reducing.

Congratulations! Here's your final answer to 20/17 + 4/5

20
17
+
4
5
=
168
85
© 2014 Randy Tayler